Size matters in the printing industry: Standardised paper formats for efficient production planning

Everyone remembers the A4 exercise book from school. In the office, a colleague may be looking for a B3 envelope. Or a DINlong flyer lands in the letterbox. But while these terms are familiar to everyone in the printing industry, the names of the paper formats are a jumble of letters and numbers for many laypeople. That's why we're taking a look at how they come about and what they mean.

Over the centuries there have been different names for certain paper formats and repeated attempts to standardise them. In 1922, the German engineer Dr Walter Porstmann developed the DIN (Deutsches Institut für Normung) format system, which later became the ISO 216 international standard used today. Among other things, he defined format A. With a ratio of 1:√2, it allows sheets to be proportionally halved without changing the aspect ratio. 

The starting point for the entire series is the A0 format with an area of exactly one square metre (841 x 1189 mm). Each additional format halves the area. So 2 A1 sheets make one A0 sheet and so on up to A8 and sometimes even A10. This system makes the best use of space and simplifies production because the paper can be efficiently arranged on the sheets and scaled for different applications. To this day, these standard formats make it easy to exchange and process printed products.

In addition to the A format, there is also the B format, which extends the range of paper sizes available in the printing industry. B formats are larger than A formats and are often used for books, posters or larger printed products where extra space is required. B formats are the untrimmed printed sheet sizes and are therefore suitable as packaging for the corresponding DIN A formats - folders, files and envelopes are therefore produced in DIN B. For example, the maximum dimensions of the German Postal Service are based on B formats.

The C format is not part of the ISO standard, but is often used for envelopes because it is a few millimetres larger than the A format, so that some A4 sheets fit perfectly into a C4 envelope. The D format is now largely obsolete. Occasionally it can still be found in the form of a DVD case. 

Other special formats are used for bespoke printed matter such as greetings cards and flyers. There are also the US letter (8.5 x 11 inches) and legal (8.5 x 14 inches) formats, which are used in North America for office and legal documents. They deviate from the ISO standard and do not correspond to the A and B formats.

Choosing the right paper format is a key aspect of print production - both for cost optimisation and for a smooth production process. Standardised paper formats provide a clear structure for the printing industry and can be easily distributed across different presses and sheets. These formats are designed for most office and commercial applications and can be efficiently processed on standard presses. Standard sizes allow for easy scalability and save costs by reducing trim waste, which is minimised through optimal sheet utilisation.

For example, a B1 sheet (70 x 100 cm) can accommodate eight A4 or 16 A5 pages, so many applications from playing cards to stationery to exercise books can be printed efficiently. B1 and B2 sheets are easy to handle and allow good material utilisation even for larger prints such as posters or packaging.

Working with the North American non-metric system can be a challenge on international projects, as these US formats often require adjustments to ISO standard sheets to optimise layout and bleed. This is not least a cost issue, as it leads to increased paper consumption. This can be partially offset by careful planning of sheet usage and selection of the correct sheet format, if the press supports an oversized B2 format with B2+, so that optimal utilisation is also possible with US formats.

Choosing the right paper format enables economical production and maximum flexibility. By optimising the combination of format choice, sheet size and trim, printers can reduce production costs and trim waste - an important step towards greater efficiency.